<template>
  <div class="todo-footer" v-show="todos.length">
    <label>
      <input type="checkbox" v-model="isAll" />
    </label>
    <span>
      <span>已完成 {{ todoDoneLen }}</span> / 全部 {{ todos.length }}
    </span>
    <button class="btn btn-danger" @click="clearDone">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: 'TodoFooter',
  data() {
    return {
      checkAllVaule: false
    }
  },
  props: ['todos'],
  computed: {
    todoDoneLen() {
      // return this.todos.filter(todo=>todo.done).length
      return this.todos.reduce((pre, todo) => pre + (todo.done ? 1 : 0), 0)
    },
    isAll: {
      get() {
        return this.todos.length === this.todoDoneLen && this.todos.length > 0
      },
      set(value) {
        this.$bus.$emit('checkAll', value)
      }
    }
  },
  methods: {
    clearDone(){
      this.$bus.$emit('clearDone')
    }
  }
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}

.todo-footer button:active {
  background-color: #da4f49;
}
</style>
